Air-spring



(No Model.)

L. SMITH.

AIR SPRING.

No. 321,768. Patented July 7, 1885.

2' Sheets-Sheet 1.

(No Model.)

AIR SPRING.

Patented July 7, 1885.

rricn.

PATENT LYMAN SMITH, OF KANSAS CITY, MISSOURl.

AIR-SPRING.

EEPECIFICATION forming part of Letters Patent No. 321,768, dated July 7,1885.

Application filed December '7, 1883 Renewed February 26, 1885. (No model.)

T all whom it may concern..-

Be it known that l, LYMAN SMITH, of Kansas City, in the county of Jackson and State of Missouri, have invented certain Improvements in Air-Springs, of which the following is a specification, reference being had to the accompanying drawings, and to the letters of reference marked thereon.

My invention is primarily designed for use as a car, wagon, or other spring. It is also applicable as a buffer for cars or railroadyards, and to various other uses wherein a confined body of aeriform fluid may be used to soften concussion. The porous nature of rubber, leather, and other nonmetallic substances used in the construction of such springs has parts in the several figures.

rendered them incapable of confining and holding the air against escape. Neither, so far as I am informed, have any of the appliances heretofore attempted to supply the loss of air been effective or reliable.

The object of my invention is to produce a spring or buffer in which the air shall be effectually confined and retained, and which shall still possess all the elasticity or strength necessary or desirable in an air-spring or buffer.

In the accompanying drawings, Figure 1 is a longitudinal section of a car-spring constructed in accordance with my invention. Fig. 2 is a plan view of the spring, the upper parts being removed. Fig. 3 is a longitudinal section of a spring constructed in accordance with my invention, but more particularly adapted to wagons. Fig. 4 is a plan of the spring shown in Fig. 3.

Similar letters of reference indicate similar Referring to Fig. 1, A is a part of the framework of the truck of a car. Bis a part of the frame of the car-body. G and Oarc the lower and upper parts, respectively, of a metallic case, which may be of any suitable shape or description. As here shown, the case is circular, as seen in the plan View, Fig. 3. The lower part, 0, of the caseis recessed at its under side, the recess fitting over the part A of the frame-work of the truck of the car. \Vithin the case 0 C is a dished sheet, a, of thin plate-steel, hardened brass, or other suitable metal, the flange a of which rests upon and extends to the outer limit or edge of the part 0 of the case. An inverted dish or curved diaphragm-plate, a, also of thin plate-steel,

hardened brass, &c., is placed above the dished plate a, its flange a' resting upon the flange a. The two parts 0 G of the case are held or clamped together, and an air-tight joint made at the flanges a a by a series of bolts, b. The central portion of the diaphragm a is recessed, forming a concave seat for the plate or enlarged head 0 of the bolt 0, and a convex seat for the lower flange, c, of the sleeve 0', whose upper flange, 0, serves to support the part B of the frame of the carbody. The nut d serves to clamp the diaphragm-plate a tightly between the enlarged head 0 and the flange c. The upper part of the flange c is provided with an annular groove, within which is inserted a rubber ring,

0. At the center of the dished plate a is pro- Below said depression vided a depression, 6. c is a pipe or thimble, 0', passed through the frame-work A and the under side of the section 0 of the case. The pipe or thimble c connects with a pipe, 6', leading to an airpump or other device for supplying air to the spring. This pump may be that used as the part of an air-brake system; or the pipe 6" may connect with any supply of air, or reservoir holding air under pressure. XVithin the depression 6 is fitted the head 0 of a valve or plug having a stem, 6", which passes longitudinally of the pipe or thimble e, and is provided at its outer end with a screwthread to which is applied a nut, c. The pipe or thimble e has a diameter greater than that of the stem 0 so that an annular air-channel is provided within the thimble around the stem 6 with which annular channel the airpipe 6' connects. By means of the nut c", which bears against the solid end of the pipe or thimble e", the head 6 of the valve can be tightly drawn into the depression 0 and a tight joint made at the depression. Thehead of the Valve or plug may be packed by the interposition of any suitable material.

Referring to Figs. 3 and 4:, a a are lower and upper sections, respcctively,of thin steelplate, hardened brass, or othersuitable metal, having flanges a a, which unite and are clamped between the sections 0 G of the case or support. The outer or peripheral portions of the plates (0 a, as seen in cross-section,are of circular form, conforming in shape with the corresponding part of the plate a of Fig.

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I. In Fig. 1 all portions of the surface or area. of the plates a a. are of the same thickness, and movement of the upper or diaphragm plate, (I, is provided for only. In Figs. 3and 4, however, the parts of the plates to a sur rounded by the outer or peripheral portions increase in thickness toward the center, at which hubs c" are formed. As in Figs. 1 and 2, the plates a a are securely attached to the case 0 C by a series of bolts, b; and in both Figs. 1 and 3 the tightness of the joint at the llanges is enhanced by an angular bend, a", and a conformation of the two parts of the case 0 C to adapt them to said bend. In Fig. 3 the air-valve, thimble, and air-pipe are of substantially the same construction as in Fig. 1, but in Fig. 3 the entire valve arrangement is attached to the lower spring-plate, a.

In operation the spring, whether of the form shown in Fig. 1 or Fig. 3, is charged with airof the required density. This is accomplished by the loosening of the nut c, which will permit the rise of the head a from the depression or seat made to receive it. Air is then pumped or let into the spring through the pipe 6'. After the spring has been properly charged with air and while the pipe 6' is still in communication with the source of supply or pressure the nut c is tightened, drawing the head 0 of the valve into its depression or seat, thus sealing or closing the interior of the spring against all communication with the outer air. The joints atthe flanges a a' and around the bolts 1) may, if desired, be tightened by any additional means known in the art. If necessary, permanent joints may be made at the flanges a a by brazing, &c., and the bolts may also be sealed by the interposition of any substance to aid a joint.

The object of the dished plate a in Fig. 1 is to prevent the escape of air through the pores of the section 0 of the casing, rather than to act as a part of the spring. It is well known that it is practically impossible to produce a casting of iron which shall be perfectly proof against the escape of air conlined within it under great pressure; hence the dished plate a, made of thin plate-steel, hardened brass, or other equivalent metal of great density, is used as an auxiliary to the casting to confine the air. Therefore the upper plate, a, in Fig. l is the only one capable of movement under the action of the spring, and it will move, cushioned by the confined air, and relieve the jar between the truck and the body of the car. The function of the rubber ring 0 is to act, in connection with the surface f of the upper section, 0, of the case, to prevent shock or undue concussion on a sudden outward movement or distension of the parts of the spring. In Fig.

3, however, both plates a a serve as parts of the spring and partake equally of the movement.

In other applications which I shall file I shall show various adaptations of this invention to various uses both as a spring and as a buffer, and I do not herein desire to claim the various details of construction which may be incorporated in such adaptations.

In my spring the central portions of the receiver are practically rigid, while the sun rounding parts are flexible. In this respect my invention differs essentially from other springs in which the movement under strain or compression effects the collapse or distension of all parts of the metallic receiver in an equal degree.

I therefore claim as my invention 1. An elastic metallic spring or buffing device consisting of a receiver rigid at its center and flexible at its periphery, and adapted to surround or inclose a body of compressed air, substantially as set forth.

2. A hollow metallic elastic spring consisting of a receiver rigid at its center and flexible at its periphery, said receiver being filled with compressed air, combined with means for attachment to the truck and body, respectively, of a car or vehicle, substantially as set forth.

3. A hollow metallic elastic spring or buffer consisting of a receiver rigid at its center and flexible at its periphery, combined with a valvular arrangement whereby compressed air may be admitted to the interior of the spring and retained, substantially as set forth.

4. In an air-sprin g or buffer, a metallic plate or diaphragm rigid at its center and flexible at its periphery, combined with the frame of the car-body, substantially as set forth.

5. In an airspring or buffer, a cast-iron case and a sheet of thin plate-steel, hardened brass, or other suitable material to render the cast case proof against the escape of compressed air, combined with a metallic diaphragm adaptcd to connect with the car-body, substantially as set forth.

6. In an air-spring, the combination of a case, a metallic plate or diaphragm rigid at the center and flexible at its periphery, and a sliding connection between said plate or diaphragm and the car-body, substantially as set forth.

7. In an airspring, the combination of a case, a hollow metallic spring iuelosed thereby,'said spring being rigid at the center and flexible at its periphery, and a connection between said spring and the car-body, substantially as set forth.

8. In an air-spring, the combination of a case, a hollow elastic metallic spring inclosed thereby,as1iding connection between said elastic spring and the ear-body, and an interposed body of rubber or suitable material to absorb concussion between the spring and case, sub stantially as set forth.

In testimony whereof I have hereunto set my hand.

LYMAN SMITH.

Witnesses:

F. CRUsn, II. B. ZnvELv.

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